[Miraste]

The idea is that the company normally prices their products at the intersection of supply and demand, where there is maximum profit. When supply is artificially constrained, they raise prices to the corresponding spot on the curve. This is not as profitable as before, but it's the new local maximum.

It's one of those simple macro-econ models that sound good, but never play out in real life because humans aren't calculators. The reality is a mix of both, probably more of your explanation.